1. Field of the Invention
The present invention relates to a n execution of an initial sequence of an image forming apparatus.
2. Related Background Art
As one of image forming apparatuses, a color printer for forming a multi-color image by repeating a recording cycle of a plurality of color components has been known. FIG. 10 shows an example of a control mechanism of such a color printer.
In FIG. 10, reference numeral 1 denotes a printer control circuit in which a video signal (VDo) 3 is form ed by an image forming control circuit 2 on the basis of an image signal of each color from a printer controller 11 and is outputted to a driving circuit 4. The driving circuit 4 is a circuit for driving a semiconductor laser (not sown) and generates a laser driving signal 5. The image forming control circuit 2 generates a video signal formed from the image signal of each color, allows an electrostatic latent image to be formed onto an image holding member (not shown), and outputs an activating signal 6 to a bias control circuit 7. High-voltage bias (transfer, development, etc.) information based on the use environment of the apparatus and the image signal of each color from the printer controller 11 has been stored in a storage circuit 10. The bias control circuit 7 uses bias data in the storage circuit 10 and generates a corresponding bias signal 8. Thus, the electrostatic latent image is developed and transferred onto a recording paper, thereby forming a multi-color image.
A detecting circuit 13D informs the image forming control circuit 2 of development cartridge present/absent information 14 or the like from a sensor provided for, for example, a developing device (not shown). An initial sequence control circuit 20D allows the image forming control circuit 2 to execute an initial sequence in accordance with a turn-on of a power source or an operation to open a door of the printer or the like. Further, the information obtained by the detecting circuit 13D is notified as information to form an image to the printer controller 11 through a video interface (I/F) 18.
FIG. 11 shows an initial sequence procedure in a door-open state by the initial sequence control circuit 20D. As shown in the diagram, a check is made in step S10 to see if the door is open. If YES, a door open initial sequence procedure is selected (step S21), the apparatus waits until the door is closed (step S14), and the processing routine is finished. As mentioned above, a predetermined door open initial sequence procedure is executed as an initial sequence process according to the door open/closed state. On the other hand, at the time of the initial process by the turn-on of a power source, a power-ON initial sequence procedure (not shown) which has separately been predetermined is executed.
There is a difference between the two initial sequence procedures mentioned above with respect to a point that, although the initialization is performed to the whole area in an RAM in the power-ON state, the initialization is performed to only a part of the area in the RAM in the door open state (data in the other area is held as it is at the preceding time). This is because in the initial sequence procedure, the RAM area to be cleared when the power is ON is made different from that when the door is open, thereby making it unnecessary to purposely reset a command which is needed at the time of the initial process and reducing the processing time.
However, as initial processes to be actually executed, in addition to the above-mentioned initial process in the power-ON state and initial process in the door open state, there are a detecting process about the presence or absence of a development cartridge or a photosensitive drum, a maximum image density (Dmax) control process, an image density halftone control process, and the like. Since the above processes are always executed when the door open/closed state is confirmed, it takes at least 100 seconds or more as a time which is required for all of the initial processes. Therefore, there is a problem such that even when the door is opened or closed for a mere jam process or the like, a predetermined initial processing time is needed.